1. Field of the Invention
This invention relates to electrical connectors and, in particular, to a connector for electrically interconnecting multiple conductive layers in a printed circuit board and a method for making such a connector.
2. Description of the Prior Art
Current objectives in circuit design include a decrease in overall physical size with a concurrent increase in component density on a printed circuit board. To meet these objectives more and more circuit designers are utilizing multilayer printed circuit boards.
One of the problems encountered in the use of multilayered boards is the electrical interconnection of the various conductive layers within the board at appropriate points. Another problem is the interconnection of discrete components or connectors to the circuit board. A third problem relates to the effectiveness of the interconnection device in maintaining a reliable, gastight connection during the life of the circuit.
Connectors which alleviate to some extent the first two problems have been disclosed in U.S. Pat. No. 3,400,358 issued to H. P. Byrnes et al on Sept. 3, 1968; U.S. Pat. No. 3,783,433 issued to H. N. Kurtz et al on Jan. 1, 1974; and U.S. Pat. No. 3,907,400 issued to R. K. Dennis on Sept. 23, 1975. However, none of these connectors adequately solves the third problem. In particular, insertion of any of these types of connectors into a plated-through hole in the multilayer board, especially where the plating is covered by oxides or other contaminants, does not ensure a reliable connection.
In some circuit applications it may be desirable to axially stack a number of multilayer boards atop one another to further increase the packaging density. Fabrication of a single multilayer board with an equivalent number of layers is often provided by cost and reliability considerations. Consequently, stacking is utilized.
While the concept of stacking is known, as evidenced by U.S. Pat. No. 3,893,233 issued to D. W. Glover on July 8, 1975, the reliability problem set out previously is not alleviated.
Accordingly, it is one object of the present invention to configure a connector which advantageously ensures a reliable connection to oxide coated or contaminated conductive platings.
Another object is to diminish the production of conductive slivers during connector insertion.
A further object of the present invention is to provide a connector which produces a nearly uniform radial pressure on conductive material on the periphery of a plated-through hole upon insertion of the connector.
Yet another object is to reduce the possibility of connector rotation during wire-wrapping operations.
Still a further object of the present invention is to facilitate axial stacking of a plurality of printed circuit boards with each board engaging a semiseparate segment of a connector.